Offset disk harrow



Dec. 30, 1947.

R. H MITCHELL OFFSET DISK HARROW Filed Feb. 16, 1944 5 Sheets-Sheet 1 ROLLIE H. MITCHELL FIG. 2

ATTORNEYS Dec. 30, 1947.

' R.- H. MITCHELL OFFSET DISK HARROW Filed Feb. 16, 1944 3 Sheets-Sheet 2 nvmvroa I LIE H. MITCHELL ATTORNEYS D 1947. R. H. MITCHELL 2,433,815

' OFFSET DISK HARROW Filed Feb. 16, 1944 3 Sheets-Sheet 3 INVENTOR. ROLLIE H. MITCHELL ATTORNEYS Patented Dec. 30, 1947 UN IT ED STAT E NT FF'I'C E. 25433 816 OFFSETIDISK HARROW Rollie -H.-- Mitchell; Huntington Park; Galifz, as-

signor: to f Killefer. Manufacturing Corporation,"- IiosAngele's; Calif.',.a corporation of California Application February 16, 19.4.4, Serial No..52 2;65.7

II CIaims. 1

The present invention relates generallyto agri cultural implements and more particularly to tandem disk harrows, with particular application to those of the offset type cornprising-asingle pair of{ front and-rear diskgangs, which are wellknown to those'skilled inthe art. Draft connections are provided between the drawbar ofa tractor andthe two disk-gangs in sucha man ner that when the tractor is driven forwardly the disk gangs are-pulled into an-angledworking position with the axes of the disksconverging in onedilection, usually towardthe left. With the gangs: in this position, no difiiculty is encountered'in making aturn to theleft, but upon making 'a turn to the right, it is necessary to shift the gangs angularlyrelative to each other-intoa positionin whichthegang axes-are at; least parallel to each other, but preferably into-aposition in which the axes converge toward the "right side ofthe implement. The force'requiredfor swinging the gangs from an angled position in one'direction of c0nverg'ence to' an angled position in the opposite direction is-obtained by means-of an offset draft connection on thetractor drawbartoone end ofone of the gangswhereby a-turn to-the right-swings the point of' connection of the offset draft member forwardly, thereby applying a force in tension td thedraft member andpulling thegangs out of angled workingposition. Under-certain operating conditions, some difficulty has-been encountered in making right turns, especiallywhen'it is'desired to turnsharply. This difiicultyarises fromthe failure-of the gangs to swingpromptly outofworking position, causing the right=end of 'the front gang to-scoop into theground, resulting-in slipping of the tractor traction wheels. Theprincipal object of the present invention, therefore,- relates to the provision of an implement of this type which-will promptly'and-eas-ily assume a reversed angled-position whenthetractor-is turned awayfrom' the direction of c'on vergenceof the axes of the gangs. More'specif ically, itis an object of my invention to provide means for urging the gangs out of working pos-i tionwhen making a right turn. Still another object relates-to the provision of means for ur ing-the gangs out of Working positionwhen mak ingaright turn, which-means is-renderedineffec tive during normal working operation.

Briefly, these objects are accomplished according to the principles of the present invention, by providing a spring connected betweenthe two gangs, which spring is stressed in-norrnalworb ing-positionto urge thegangs out of'angledworking position. During-norma l'operation, the har row is locked in angled working position to"ren-" der the spring ineffective; thus preventing the gange. from slipping out of angled position during forward movement. I

Theseand other objects and advantages 'of'my invention will-be 'apparent" to those skilled in the art aftera iconsid'e'rationfof the follow descripe tion, reference being had tof'thedrawmgs 'apf pended hereto; in-whichf Figure. 1 is a P an wi n" fii'ei k 113 row embodying the principles 'of the present in vention, and shownin a parallehor transport position; V v K Figure" 2 is an, elevationa1 viewtaken along; a lin 2* 2 in" Figure 'l-"a'nd showing 'on a larger scale the details of the angle control -mechani:snfr.

Figure i a P lfY W' of i rmwi h w in anormal'working position,

u e @1818; pi nv ew w he mw in arightturn position: r

Referring now to the drawings; the harrow comprises a pair" of front and' rear gang h omnr is n a en ra l r 'e en iflar 'l,upon ',w1'lich is mounted-a gangshaft fi'on which em im d a ur li y. o l te a aced d k 9; inc-any suitableconventional manner;'; Theftwo gangs: 5;" 6 are swingably' connectedtogether by means of"two"pairs "of crossed links l il'j l I'i. each pair comprising upper andflower'lirikbarsspaced apartvertically-'above-and below th'eframe'mem bers and pivotally' connected thereto bymeans iof suitable pivot pins! 2. p

Draft-is applied-to.thetharrow by meansofi'a hitch frame l5,"which 'comprisesfia transverse'bar l6 pivotally connected: by 'ineans "of pin ll'fto an ear IBfiXedto:the'frontfitransverse member l9 ofthe front'gang frameili 'Thef'oppo'sitejend of the transversahitch'bar l 6' is*connect ed"by ea s," O a edili k m be 2 t e mm left hand corner-of thefi'amer Ton" the: rear "gang 6: The forward: endofthe'link'memberg'fis bent downwardly and passes through asuitjable opening; in the left 'han'd end "of; the .bar" "I G and the" link' 21 extends rearwardly; lying over'the top ofthe front gang Wandis'pivotallyconnected by means'of a pin 22 to therrear-gang frame l'. A strap member" 23. is fixedtG the front gang frame member I Qr'and lies' ovei:the-link 2 l permittinglateral swinging'movement of the 'jl inki 21 but preventing-verticaldisplacement of; thahitch bar l6 relativeto thegang frame-T. Thetransverse'hitch bar l6 is connectedito-a pair offorwardly converging draft members "214; Whilcnare pivotally connected together" at J their' forward ends at 25 and are bolted to the transverse bar l by removable bolts 25. The draft members 24 can be adjusted laterally by removing the bolts 25 and replacing them in any of a series of holes 21 in the transverse bar it. The forward end of one of the bars 24 is pivotall connected by means of a draft pin 28 to the U-shaped drawbar 29 of a tractor. Each of the draft members 24 is provided with a pivoted joint 35 to permit the draft members to swing vertically during operation.

The angle of convergence of the two gangs 5, 5 in operating position is controlled by angle control mechanism including an angle control bar 35, which is pivotally connected to the rear pivot pin I2 of the link H. The angle control bar 35 extends forwardly from the pivot pin l2, and lies over the top of the front gang frame. A U-shaped strap member 35 lies over the angle control bar 35 and is rigidly fixed to the front frame member I9 of the forward gang frame, permitting the angle control bar 35 to slide fore and aft through the strap 33, but preventing lateral swinging movement of the bar 35 relative to the front gang.

The harrow is pulled into angled working position by driving the tractor forwardly, thereby imposing draft upon the right end of the front gang through the pin I1, and to the left end of the rear gang through the link 2|, thereby pulling the harrow into the position shown in Figure 3. This causes the angle control bar 35 to be pulled rearwardly through the strap retainer 35 and the working angle is determined by means of a latch carriage 31 which is slidable along the bar 35. The carriage 31 comprises a pair of upper and lower plates 38, 39 disposed above and below the bar 35 and secured together by bolts 40. Rollers 4| are journaled on the bolts 40 and serve as guides on oppositesides of the bar 35 to facilitate movement of the carriage 31 along the bar 35. The carriage 31 is locked in adjusted position along the bar 35 by means of a latch dog 42, which is pivotally connected to the plates 38, 39 by means of a vertical bolt 43. The latch dog 42 is engageable with any of a plurality of notches 44 in the side of the angle control bar 35, the latch dog 42 being shiftable out of engagement with the notches 44 by means of a control lever 45 pivotally connected at 41 between the plates 38, 39 and connected to the dog 42 by means of a link 48. The lever 45 is controlled from the tractor by means of a rope 49, there being a spring 53 provided to return the control lever 46 to locking position when the rope 49 is released.

Thus, as the tractor is driven forwardly to angle the harrow, the rope 49 must be pulled to unlock the carriage 31 and permit the bar 35 to slide rearwardly relative thereto. When the harrow is in the desired working angle, the operator releases the rope 49 and permits the latch dog 42 to engage the nearest notch 44,.whereupon the carriage 31 is pulled into engagement with the strap member 36, thereby preventing any further rearward movement of the angle control bar 35, and thus limiting the angle of convergence between the axes of th gang shafts 8.

The gangs are also locked against angular movement out of working position by means of a latch dog 55, which is rigidly fixed to a transverse rockshaft 56, which is journaled in a plurality of bearings 51 attached to the front frame member IQ of the front gang 5. The latch dog 55 engages the front side of a projection 58 (see Figure 2) welded to the bottom of the lower plate 39 of the carriage 31. Thus, the gangs 5, 5 and bar 35 are disengageably locked against horizontal angling movement in either direction.

The gangs are swung from the normal operating position shown in Figure 3, in which the gangs converge toward the left to the right turn position shown in Figure 4 in which the gangs converge toward the right, by means of a draft chain 65, which is connected at its forward end to an arm 66 which is rigidly fixed to the tractor drawbar 29 in laterally offset relation to the draft pin 28, to the left of the latter. The rear end of the chain is connected to a depending lever 31 comprising a pair of arms rigidly fixed to the rockshaft 55 at the left end of the latter and hanging downwardly therefrom. The rockshaft 55 is urged by means of a coil'spring 68 encircling the right hand end of the rockshaft 55 and anchored to the adjacent rockshaft bearing 51 tending to urge the rockshaft in a clockwise direction as viewed in Figure 2, until the lower end of the lever 51 engages the front frame member l9.

When the tractor makes a right turn the drawbar 29 is swung to bring the offset arm 65 forwardly, thereby applying a forward pull through the chain 55 to the depending arm 61, until the latter is extended forwardly, thus causing the rockshaft to rotate in a counterclockwise direction as viewed in Figure 2 and forcing the latch dog 55 rearwardly past and under the projection 53, thereby permitting the angle control bar 35 to shift forwardly relative to the front gang as the draft force applied through the chain 55 pulls the left end of the front gang forwardly. At the same time, a force in compression is applied through the hitch frame l5 to the right hand end of the front gang and thus the force couple set up by the chain 65 and hitch frame l5 forces the gangs into the right turn position shown in Figure 4. This is done automatically without attention from the operator when the tractor is turned to the right. When the tractor is again straightened, the tension in the chain 35 is relaxed and the tension applied to the draft frame l5 pulls the harrow into its normal working position once more. The chain 65 is passed through a ring 59 mounted on the left end of the transverse hitch beam !6, to support the chain when the harrow is in operating position as shown in Figure 3, to prevent the chain from dragging on the ground.

Further details of construction and operation of the control mechanism in a harrow of this general type is contained in Patent No. 2,169,471, granted August 15, 1939, to Sjogren and myself.

A heavy tension coil spring 10 is connected at its forward end to an eye ll welded to the top of the strap member 35, and is connected at its rear end to a lug l2 rigidly fixed as by Welding to the top of sleeve 13. The sleeve 13 is slidably disposed upon the angle control bar 35 and is free to slide longitudinally thereof. A collar M embraces the angle control bar'35 ahead of the sleeve l3 and is provided with a set screw i5 for rigidly securing the collar 14 to the bar 35 in any desired position of adjustment. The sleeve 13 is prevented from rotating relative to the bar 35 by means of a rod 16, which is rigidly attached, as by welding to the collar 14 and extends rearwardly therefrom alongside the sleeve 13 and through a small collar'or thimble ll which is rigidly fixed to the side of the sleeve l3. Thus, the sleeve 13 is free to slide longitudinally along the angl controlbar 35 but is held in a position with the lug l2 uppermost by means of the thimble 11 and rod 16, and it is also limited in its forward movement relative to the bar 35 by mean of;t l1e fixed collar 14. It is now evident that when the tractor is driven forwardly to angle the harrow, the spring is stressed in tension as soon as the sleeve 13 is pulled into engagement with the fixed collar 14.

After the angle between the gangs has been determined by the operator releasing the rope 49 and causing the latch dog 42 to engage one of the notches 44, the spring H3 is prevented from pulling the gangs back to a lesser angle, by virtue makes a right turn, which releases the latch dog '55 as explained above, rendering the spring effective to assist the draft chain 65 in promptly swinging the gangs to a reverse angled position to facilitate the right turn, as indicated in Figure 4. In this position, it will be noted that the sleeve 13 is shifted rearwardly along the bar 35 away from the fixed sleeve M, rather than buckling the spring as would be the case if the spring were connected directly to the collar 14. When the tractor is straightened once more, the right hand ends of the gangs are spread apart, thereby taking up the lost motion between the sleeve 13 and collar 14 and then stretching the spring 10, as shown in Figure 3.

, Th spring 10 also facilitates closing the harrow to parallel position for purposes of transport, which is accomplished by pulling the rope 49 and backing the tractor against the draft frame I5, thereby pushing the right hand end of the front gang rearwardly, thereby returning the harrow to the position shown in Figure 1. During this operation, the carriage 31 is locked to the front gang frame by means of the latch dog 55 on the rockshaft 56, whereby the rearward movement of the front gang relative to the rear gang causes the angle control bar 35 to slide forwardly through the carriage 31.

I claim:

1. Inan implement comprising a pair of front and rear gangs of ground working tools swingably connected together by means providing for relative angular movement in a generally horizontal plane into and out of angled working position and draft means connected to said front and rear gangs and adapted to be coupled to a tractor, a tension coil spring connected at one end to one of said gangs, a lost motion connection between the other end of said spring and the other gang in laterally offset relation to the swingable connection between the gangs, said lost motion connection being disengaged when the gangs are in a, parallel transport position to prevent the spring from buckling but engageable asthe gangs are moved toward working position, said spring being adapted to be stressed by movement of said gangs into said angled working position, the force of said spring acting to urge said gangs out of said working position.

2. In an implement comprising a, pair of front and rear gangs of ground working tools swingably connected together by means providing for relative angular movement in a, generally horizontal plane into and out of angled working position and draft means connected to said front and rear gangs and adapted to be coupled to a tractor, a tension coil spring connected at one end to one of said gangs, and means for adjustably connecting the other end of said spring with the other of said gangs at various distances from said one end to increase or decrease the spring pressure between said gangs, said springs being connected in laterally offset relation to said swingable connection to stress said spring by movement of said gangs into said angled working position, the force of said spring acting to urge said gangs out of said working position, said adjustable connecting means including lost motion means preventing said spring from bucklast mentioned gang and a lost motion connection between the other end of said spring and said bar, saidspring being so connected as to be stressed by movement of said gangs into angled position, to urge said gangs toward said non-working position and said lost motion connection being adapted to separate when said gangs are in said non-working position to prevent the spring from buckling.

4. In an implement comprising a pair of front and rear gangs of ground working disks swingably connected together by means providing for relative angular movement in a horizontal plane between a parallel non-working position and an angled working position, and means for controlling said angular movement comprising a longitudinally extending bar adjustably interconnecting said gangs, a sleeve slidabl on said bar, spring means connected between said sleeve and one of said gangs, and means for adjustably connecting said sleeve to said bar in various longitudinally spaced positions thereon.

5. In an implement comprising a pair of front and rear gangs of ground working disks swingably connected together by means providing for relative angular movement in a horizontal plane between a parallel non-working position and an angled working position, and means for controlling said angular movement comprising a longitudinally extending bar pivotally connected to one of said gangs, disengageable means for locking said gangs and said bar in a horizontally rigid structure, a sleeve slidable along said bar, means for adjustably connecting said sleeve with said bar at various points therealong, and a spring connected between said sleeve and the other of said gangs and effective upon disengagement of said locking means, for urging said gangs from said angled position toward said non-working position. v

6. In an implement comprising a pair of front and rear gangs of ground working disks swingably connected together by means providing for relative angular movement in a horizontal plane between a parallel non-working position and an angled working position, means for controlling said angular movement comprising a longitudinally extending angle control bar having one end pivotally connected to one of said gangs, means for disengageably locking the other end of said bar to the other of said gangs, a sleeve slidable along said bar, means for connecting said sleeve to said bar in longitudinally adjusted position, and a sprin conne d between said sleeve and :the other .of said gangs and reflective up n dis n a em nt of sa d .z qekieg .mea

I r in i an s from sa d an d 1 9511 191 @9- Ward said non-working position.

'7. In an imp nt mn ine avai .0; Kent and rear gangs of ground workin xtools swingably connected together by means providing for relative angular movement in a generally horizontal plane into and outof angled working position anddraft means connected to saidirontand rear gangs for transmitting a iorward draitiorce to pull said gangs into said angled working position and adapted to transmit 'a draft foroeinan vangle in one direction to close said gangs to said non-workin pos ion, a lon itu nall extend n angle control bar having one end pivotal- 11y veonnected to oneof said gangs, means ;f or dise ng;age-

ably locking the other end of said bar to the other of said gangs to look s id gan s, draft connections, and control bar in a ,hori ontally rigid structure, sleeve slidable zalongsafidzbar; means for connecting said sleeve to said bar in longitudinally adjusted position, and a spring connected between said sleeve andsaidother gang,

said spring being stressed by movement of said gangs into said working position and eefiflcfiive,

.upon disengagement of said looking means, or

ur in s i an t w r saidnon-iwor ing po i- .tion.

8. In an implementoomprising a ,pairof front and rear gangs of ground workingldisksswin ably connected together ;by ;means providing for relative angular movement in a horiZQnl/al plane between a parallel non-working position and an angled working position, :means'for controlling said angular movement comprising a longitudially extending bar interconnecting a-said gangs and .shiftable relative to one-ofthelattenalsleeve -slidable on said bar, spring means connected :between said sleeve and saidoneof saidgangs, and

as r oll fixe to s i 'ba asainst whic said s e e a t hen't e eanssia eshif dt ward working position, providing a ;lost ,In t en s ble when s id enes a e shifted to non-working posit on t pre ent ,bncklin 'ior the in n limn em n compr i a pain-of ,front and rear ee ie e ound wqrkingflisks swin va e on ee h by im ansm v ding :fo

relative angular movement in a hoi ntal :plane between a parallel non-working posi t on and an a led Working ositi n meanier .c nt le in said angular movement comprising -a iongi;t udinally extending bar interconnectingsaid gangs and shiftable relative toone -of.tlielatter, a sleeve .slidable onsaidban-spring means conneoted petween said sleeve andrsaid one of'sa id gangsa stopvcollar .slidableonsaid barrandmea for f xing said collar to said bar longitu nally adjusted position, said. collar ,actingl-as anla utment against which said sleeve bears-to stress said spring when the gangs are shifted toward said working positions, the lte nsionin said spring b in adiustable y be 20 terrelative to said bar.

adjustingsaid collar onsaid impl ment eempris ear r of om and rea ene ;st redWo kin k Win ed connected together by means providing for rela tive angular movement in a horizontal plane between a para lel nonk g p s t on d an are ed Workin o t o e n or convening said angular movement comprising a longitudinally extending bar interconnecting said gangs andshittable relative to one of the latter, a sleeve slidable on said bar, spring means connected between said sleeve and said one .of said gangs, a

stop ,-co1lar s lidable on said bar, means for fixing said collar to said bar in longitudinally adjusted position, said collar acting as an abutment against which said sleeve bears to stress the spring when said gangs are shifted toward said working position, the tension in said spring being adjustable by adiusting said collar on said bar, and 'coope rable guide means on said collar and .onsaid sleeve for preventing rotation of the lat- ,1 1. In an implement comprising a-pair of front and rear gangs of ground working tools swing,-

abl y connected together by means providing for 'to the other of said gangs to lock said gangs,

draft connections, and control bar ina horizontally rigidstructure, .avsleeve s'lidable along said bar, means foiaconnecting said sleeve to saidvbar in longitudinally adjusted position, anda spring connected between saidsleeve and said other sane, sa d s rin b in stressed by move en e said gangs into said working position and effective, upon disengagement of said locking .means, for urging said gangs toward said noneworking positiomsaid sleeve connecting means comprising a stop collariixed to said bar against which said sleeve abuts when the gangs are shifted toward working position, providing a lost motion connection separable when said gangs are shifted to non-working position to prevent buckling of the pr n ROLLIE H. MITCHELL.

E E ENC S CITED lhe following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,710,124 Traphagen Apr. 23, 1929 1,832,027 Johnson Nov 1'7, 1931 2,169,471 Mitohell Aug. 15,1939 

